Camped By a Billabong

Most Australians know the song “Waltzing Matilda”: 

Once a jolly swagman camped by a billabong
Under the shade of a coolabah tree … 

As that swagman was camped under a coolabah, there is a fair bet he was up along or near the River Darling. Many inland streams had Eucalyptus coolabah growing on their banks—and perhaps there were E. camaldulensis (river red-gums) too, but he would have been wise to the way they drop limbs on hot days. And a coolabah was more pleasant tree to camp under than the other common tree, the black box (E. bicolor).

A billabong, strictly meaning a loop of water a bit apart from the main stream of a river, was often a nice body of water, replenished by floods, perhaps also by some seepage, and retaining water longer than the main flowing stream. The swagman would have known this, so much better to camp there than along a small stream that might flood or dry up. Some other bodies of water provided good camping too: oxbows (rather more curved and more connected to the main stream), lagoons, and in later times the manmade pondages for special purposes: dams, reservoirs, locks. Here we will group bodies of water, either nature’s own or human works, under the euphonic Australian word, billabongs. These structures are an integral part of the landscape accommodating the “flooding rains” of Dorothea Mackellar.

Of course the squatter valued billabongs too, frequently using them as his basic water supply—for his sheep and quite likely for his homestead. So there were jumbucks—sheep—about, coming down to drink. Thus our swagman had meat and drink.

In earlier times the Aborigines would have camped by a billabong—with kangaroos and other game coming down to drink. They, too, would have understood the relative permanence of a billabong, and one can suspect that they sometimes threw some logs across to catch silt, build up the embankment, make a bigger billabong, a more reliable and longer-lasting water supply. Our European ancestors did the same thing with increasingly helpful mechanical equipment.

Water supply must have always been a preoccupation of humans in drier lands: having drinking water from one rain to the next, so camping near billabongs, using containers to carry and store water. In these days of polythene pipes and other modern materials many aids are taken for granted, but there was a beginning. Some plants, like bamboos, provided useful tubes and were cobbled together in amazing ways to pipe water. Animal skins were made into carriers, gourds and melon shells were good short-term receptacles. Slowly technologies were developed that enabled people to camp away from billabongs on sites with other merits, such as better soil or higher ground away from floods or having views or strategic defence locations. They built villages, which developed into towns and cities—often destroying the original amenity, the good land near a billabong, as town growth was inadequately controlled.

Pumps and pipes enabled reticulation, which has been the crowning achievement. It has meant extending supplies from the billabongs using channels or big pipelines, then smaller pipes down to very small pipes putting water into every desired location—the bathrooms and toilets of the family home, and even intricate tube systems watering the garden, often with timers or soil moisture monitors. Most dramatic has been the overcoming of gravity, no longer having to use water just within the catchment, but pumping it over—or under—the hills and far away.

Some ancient cities had gravity-fed supply systems. Massive aqueducts, some in fair condition, still stand in central Spain and Tunisia. By Roman times some cities had piped supplies, such as the port of Ephesus in western Turkey, which had terra cotta pipes 7 to 10 centimetres in diameter, about 30 centimetres long, each joined to the next by a lead seal, delivering water from mountains more than 20 kilometres away. Learning to lift water by other than human direct effort was a great development. Archimedes invented the screw, turning a spiral in a tube to pull water up. The Chinese used a version of the screw, co-ordinated to lift water up slopes and irrigate rice paddies on the contour. At the same time hand or treadle-driven wheels scooped up water in cups and tipped it into a channel at a higher level. In the reverse of the process a stream of water filled cups and turned a wheel—water power, beginning the industrial revolution.

In due course came all sorts of devices for pumping water, such as reciprocating pistons in cylinders, powered by human energy, then wind—what a boon was the windmill. With fuel engines and electricity driving rotary pumps, humans could do almost anything they wanted with water at a considerable distance from the billabong. Earth-moving equipment—first the shovel then large scoops on tractors—enabled the creation of billabongs of immense size, storing huge volumes of water.

Evaporative and soakage losses have dogged many human activities, but the combination of dams and pipes has enabled the placing of big new billabongs in near perfect sites—deep water with lower evaporation, greatly reducing costs per unit of water stored and delivered.

Dams and similar structures were once loved by Australian politicians; a big new billabong, ideally full to the brim, was a great photo op. “Build another dam, it will fill.” Only hindsight could inform us that the golden years of dam building from the 1950s to the 1980s were wetter than average, with big stream flows. (Lake Eildon was expected to take two years to fill: it filled the year after completion, 1956.) In recent times there has been the added “problem” of conservation farming absorbing rain more effectively, so flows have been lower and lower. Sometimes weirs and locks for shipping transit helped provide water.

Then the rise of some conservation movements, and the establishment of the Greens, brought antagonism to interference with stream flow, with the abandonment of the Franklin River dam in Tasmania a key event. Soon, for a politician, advocating dams, let alone a photo in front of one, could be the kiss of death.

Structures protecting saline from mixing with “fresh” water were important features: like the barrage where the Murray River waters met the sea—a mouth with lakes and sandbanks. At high tide and low river flow the salt water rolled across the lakes and up the river past the town of Murray Bridge and as far as Mannum. Completed about 1940, closure of this barrage enabled the exclusion of sea-water from the lakes and lower river. In the event, the wetter years and greater stream flow meant the lakes became fresh and were used as a source of water for farm irrigation. These really big billabongs attracted far more than swagmen: young dairy farmers, my kin and neighbours from my youth in the Adelaide Hills, found they could run much larger herds and make much larger profits. Thus there was pressure to open the barrage only on rare occasions.

South Australia provides an interesting example of water reticulation development. The nature of the rainfall patterns, the terrain and the soil types meant that settlement was limited and water supply would always be a huge problem. The site of the capital at Adelaide had been chosen over Kangaroo Island and Port Lincoln partly on the basis of water supply: Adelaide had the billabongs of the Torrens River flowing down from the hills. As the settlement grew there was need for more water so the settlers built some more billabongs upstream and on some nearby streams.

But those streams soon proved inadequate, and so a dam was built at Happy Valley, capturing several small streams flowing from a well-watered area around twenty kilometres south of the city, with a pipe to the city. Within fifty years this, too, was inadequate so, in a bold development, a pipeline was laid in the late 1880s from a weir on the Onkaparinga River at Clarendon, through a tunnel several kilometres long to Happy Valley reservoir. The Mt Bold Reservoir was built upstream on the Onkaparinga River, enabling the level of the Clarendon Weir to be maintained and giving Adelaide a good supply.

The waters from some small streams in the hills near Port Lincoln had been gathered into the Tod River Reservoir and supplied to Port Lincoln. With the support of Sid Kidman, in the 1920s a pipeline was laid more than 400 kilometres to Ceduna—downhill all the way. For years this was the longest gravity water supply in the world, delivering water far from any billabong, with branch lines providing stock and domestic water to many small settlements and a vast area of farming land. Underground basins of good water were later found under the limestone at various places and this supplemented the Tod River Reservoir water.

But Adelaide had an unquenchable thirst, and grew so large that in 1945 the Premier, Sir Thomas Playford, announced that Adelaide was going to put a pipe into the big billabong, the Murray River, at Mannum. The water would be pumped up to the top of the Mount Lofty Range and would flow into the streams there, thence to the Adelaide storages.

There was more. Whyalla is one of the driest places in Australia—annual rainfall of 125 to 150 millimetres—but in its hinterland there was iron ore, hills of it. Water was needed to process this ore and for the workers’ towns—and there was no billabong within cooee. Playford didn’t hesitate—all that was needed was another pipeline from the Murray, at its nearest point, Morgan, and so it came to be, in the late 1940s. As the pipeline passed near the towns of Port Pirie and Port Augusta, its water also helped them become more pleasant places to live. Needs grew and in a couple of decades the pipeline was duplicated, then in due course it was extended to the Eyre Peninsula scheme, initially as a back-up and increasingly substituting. Woomera had been developed as a rocket range—out in the desert. It, too, had a pipeline from the system. With many smaller pipelines, South Australia became a model of water reticulation.

Melbourne was established on the Yarra—soon with fresher water diverted from above Dight’s Falls—and the Maribyrnong was tapped. When Melbourne outgrew these supplies it was fortunate to have a well-watered forested catchment to the east, providing very high quality water and having some good sites for dams. Only in recent droughts has Melbourne sought to put a pipe from what is seen as someone else’s billabong, the Goulburn—and the “squatters” of the north have “mounted their thoroughbreds” and driven down to protest. In addition the new sea-water desalination plant can now provide the ultimate back-up—absolutely independent of rainfall.

Perth found the Swan was a good supply and with the streams in the Darling Range in the 1890s there seemed to be spare water to pump some to Kalgoorlie, 300 kilometres away, enabling gold mining and bringing wealth to the colony. Fortunately there was a lot of water under the Post-Miocene sands on which Perth was built, so as it grew and needed more water, modern pumps made this water accessible, deferring shortage. Perth, too, has a desalination back-up.

Brisbane had some nice billabongs—but replen­ish­ment often came as a flood. The swagman of our song could break camp—but being less prudent than he was, later people built permanent buildings. Flood plains are an integral part of the “camped by a billabong” story. In many areas we should have copied the swagman and stuck to camping—moving away quickly when the rain came and the river rose.

The Murray River has had a long and interesting history, not well known to most people. Its basic function has been draining and eroding the eastern ranges and forming broad areas of good soil by depositing silt on the western plains. As befitted a mature stream, its course shifted about, especially in the lower reaches.

Before European settlement, or even the stories of the dreamtime, back ten million years or so things were very different. The river flowed west from near what we call Barmah, through what we call Mathoura to what we call Swan Hill—from the air one can see the old river bed. Then a small fault block was uplifted, perhaps twenty metres or so, more or less from Echuca in a northerly direction to Deniliquin. This dammed the river, creating a large but shallow billabong upstream, great conditions for the establishment of a huge new river red-gum forest which we now call the Barmah Forest and Wetland. The river eventually divided, about a third of the flow forming the Edward River, flowing through Deniliquin, and joining the Murrumbidgee, the remaining two-thirds of the water flowing around the south end of the fault and through Echuca as the Murray River.

The main Murray flowed south-west of where Kerang is, merging with streams draining from the southern ranges, and its mouth was somewhere in the Wimmera, around Horsham, the main evidence of its past presence a wide delta of silty material forming the rich Wimmera farming soils. It discharged to the west into a vast bay—the Gambier Embayment of the Southern Ocean. This was an inlet from Robe in the south to Goolwa in the north-west and indenting possibly as far as Nhill, with arms much further inland, even nearly to Swan Hill.

Then came a period of acute climate change—the Great Ice Age of the Miocene. It is suggested that during this period sea level fell and because of the gently sloping sea bed, the coastline retreated a long way south-west, exposing a vast area of sand and shelly, calcareous material on the floor of the embayment. The prevailing wind was on-shore from the south-west, and it moved sand and calcareous debris east, filling up the embayment and forming the current parallel sand dunes with inter-dunal flats from the coast to near where Naracoorte is. This closed up the Murray mouth, just as the later mouth at Goolwa is being blocked up now. Eventually some of the sands rolled on east to form the Big and Little Deserts. The calcareous material provided some caverns and aquifers underneath.

With its mouth blocked and possibly some more faulting, the Murray wandered, filling another basin, the Koondrook wetland that became another red-gum forest. It wandered north-west to where Mildura is—so, recently in geological time (what we call the Post-Miocene) Mildura ceased to be a desert place: it had billabongs. The river eventually flowed on to Morgan, and then somehow south to Murray Bridge and Lakes Alexandrina and Albert, perhaps meeting an old stream flowing from the Flinders Ranges. Under the area that was the embayment there are some old underground relic streams, providing water in various places, even some water emerging at Salt Creek on the Coorong.

The first European settlers found a river whose flow was at times intermittent—reduced to trickles between billabongs. Since then various dams and locks have made it an intensely managed river—a fine series of manmade billabongs. The diversion of the Murray to its present northern route in the Post-Miocene era was fortunate for South Australia—just imagine it without its widely reticulated Murray water.

Victoria appeared to have a lot of water available, and Victorians built many dams. Movement of water across the landscapes was aided by the topography—water could be moved vast distances by gravity. The carrying of water from the Goulburn near Nagambie right across to the Mallee is a great example. The State Rivers and Water Supply Commission, led by men of the calibre of Ronald East and Alf Tisdall, could conquer anything! In the interests of economy they used earth—rather than concrete—channels and tied the irrigation water to the title of the land, aiming to lock water to land well-suited to irrigated crops.

Sustainability has become a widely used word, but users of the term have not always recognised that it means that the practices used must be envisaged as being able to be repeated forever. Unfortunately management groups have frequently not understood the salt issue—that sustainability mandates the passing out to the sea each year of enough salt so as not to have more and more—ideally even less and less—in the catchment. The origins of the salt need to be clearly understood. Though some is from ancient sea beds, such as the Gambier Embayment, a fair proportion is from rain. Much of the rain falling on southern Australia comes from air masses arriving across the Southern Ocean, and carrying dissolved salts, mostly sodium chloride. Thus up to a million tonnes arrives in the Murray-Darling Basin each year, and unless an average of this amount returned to the ocean annually the catchment becomes increasingly saline.

Before European settlement and various billabong structures, the unimpeded flow of the rivers might well have taken a large proportion of this salt back down its stream bed to the ocean, especially in flood years. In recent times the main river has increasingly become a channel to provide a high-grade water supply, so some effort is put into keeping the salt level low, for instance preventing lower-grade saline water from draining into it. Thus salt is retained in the landscape. The cost of providing the high-grade supply should include providing a system for gathering the salt and returning it to the sea. Basically this would be a system of pipes and ponds and pumps, possibly including the staged lift of concentrated saline water over the Great Dividing Range, using new energy technologies, solar and wind power to lift and possibly generating some return energy in flow down to the ocean. There are possibilities for incorporating bathing in high flotation ponds and raising sea fish, as the Egyptians have set up along the Nile.

Emerging technologies have enabled us to do so much better than the swagman, to decide where we want to live, in houses rather than camps, and what we want to do, and set structures to deliver water accordingly. What are the limits? New pipeline and channel technology would enable efficient movement over great distances—yet the opposition party in Western Australia was ridiculed by the Labor Party and the media for planning to bring a very small percentage (about 3 per cent) of Fitzroy River water to Perth. The idea was to use mostly a covered channel with a sealed-bed to cut seepage losses, and a cover to reduce evaporation. It was argued that this was nearly as efficient, and possibly much cheaper than a pipe.

J.J.C. Bradfield suggested turning Queensland rivers inland into the Darling system—but who dares utter his name today? Yet the feats of my grandfather’s time—he worked on both the Clarendon weir project in South Australia and the Goldfields scheme in Western Australia— faced much more daunting challenges. Their works and the massive Snowy Mountains Scheme are to be admired in every aspect—both technological and political, products of the courage of politicians like Playford and Chifley and technologists like East and Tisdall and Hudson.

Where to from here? Perhaps events in Tasmania are a good portent. Dams were especially “taboo” there, but they have sneaked back, and they are an important plank of the “Clean and Green” food production of Tasmania. “These irrigation dams are very different,” said the Premier, Lara Giddings, in December 2011. “This is not a dam the size of the Hydro dams. This is not like the old dams debate … It will make Tasmanian agriculture economically and environmentally sustainable.”

And Queensland has taken the same line. Not for them the big dams either—rather a “mosaic” of smaller billabongs funded by the farmers themselves to service their needs. Former Premier Anna Bligh and former National Regional Development Minister Simon Crean boldly committed themselves to this program with a photo op against a water background. They provided $3 million for “on-farm trials” to assess water storage options, and were scathing of the federal Opposition proposal to build larger centralised dams. Heartened by the great flooding rains of 2011 and 2013, the Opposition is seeking new billabong sites in northern Australia with some new crop production.

But perhaps we should have another look at Bradfield. Though we may welcome the signs that the blanket “green” ban on new dams is being gingerly lifted and small units are tentatively suggested, we need to remember the engineering principles, to heed the advice of water experts. For a given total storage of water, the fewer the number of dams usually means lower cost per unit of storage. And the lower the total surface area the better—over most of Australia the evaporation from a free water surface is at least 1.5 metres per annum. Thus, finding sites for large, deep dams in the mountains and using pipes to deliver water to the irrigated farms—which are normally out on the plains—is far more efficient than having many smaller farm dams on the plains. And surely new technologies will enable grander plans; solar and wind energy are great examples of technologies awaiting wider utilisation for the small lifts needed to cut corners and complement gravitational movement.

There are some interesting new pipes—traditionally large pipes were made from reinforced concrete, so were heavy and costly to transport and lay, and inflexible. What are called GRP pipes are a contrast: a spun tube of fibre glass, lined with a film of resin, then finished with a layer of polymers. They are light and have some flexibility, and can be “nested” for transport. German technologists have made them up to four metres in diameter, so in a sense they are a storage as well as a conduit. (The Germans suggest there are some possibilities in an associated activity—treatment and disposal of sewage. Instead of treatment ponds or fields, a “mass” of material would be edged along a section of three-to-four-metre GRP pipe; extra digestive chemicals would be added at places, the water would be drained off the bottom, all gases, mostly methane, would be captured along the top for a power generator, and the compost at the end would be analysed for nutrients and priced accordingly.)

Very high rainfall must be a caution, not a magnet. Constant awareness of drought and water needs in the south is making northern high rainfall areas more attractive, but they can be a snare and a delusion. It is easiest to produce quality products where the growing season has just enough water (from rain supplemented with irrigation), with warm dry weather for crop ripening and harvest. If areas are too moist and therefore of high humidity, grain may sprout in the head, fruit may split or have mildew on it, pests may thrive. Thus for many crops the higher rainfall sub-tropics are risky—part of the value of the Ord is that it is a bit further south, drier, not wet tropics.

There is a strong case for well-designed diversions into the Darling system, then using more efficiently the mature social and technical structures of our existing irrigation areas. There may be the need for some review of the rules of water trading to minimise the sort of waste that comes from stranded assets—irrigation farms from which the water has been sold and the authority will no longer maintain channels.

There are periods, often lasting more than a year, when there is more than average water in the system—billabongs all full, the soil profiles all well charged—and the opposite when the soils have dried out and the river is carrying less water. Perhaps we should look at incentives for more water use in the flush times. What we must avoid is over-commitment to uses that need water in the drier periods. Cotton and rice are often demonised but in fact the amount grown can be varied from year to year, and the products can be stored, whereas vines or trees need much the same amount of water from year to year. There could be special “tenders” for more water use on rice and cotton in the periods of plenty.

In dealing with the Murray-Darling Basin we are torn between what was—at European settlement or much earlier—and what we would like things to be. The swagman and the squatter came by and took water and other amenity, but didn’t do much else—they could be accused of not managing the resource. But they were of their times and should be judged accordingly. It is fashionable to say that we have had 100 years of mismanagement of the Murray-Darling basin, but it is fairer to accept that our ancestors along the river were of their time and should not be judged by the latest knowledge—or whims.

Recognising the Post-Miocene situation, when the river ran elsewhere and did other things, may be a start in freeing up our minds, giving ourselves permission to dream as we camp by our billabongs. Awareness of the Gambier Embayment suggests we consider drainage water from the south-east of South Australia as part of the equations—draining this water into the southern end of the Coorong and classing it as Murray system environmental flow. Perhaps most of all we need to remember the boldness of our ancestors in the century before last, tunnelling through the Adelaide Hills and pushing water up from Perth to Kalgoorlie to enable gold mining.

Today many people are inclined to see change in the billabongs as “future eating”—to use Tim Flannery’s term. But we could be future making, for example by viewing the Murray-Darling Basin as a vast factory converting solar energy and carbon dioxide into products needed by humans, especially by 2050 when there will probably be 9 billion of us. With all the basic parts of the factory already in place—water structures, towns, amenities, transport, innovative people in food growing and all of the supporting trades and professions—it does not make sense to close parts of it down. Surely we ought to maintain or increase the water for production, especially by pouring more into the top end and adding all possible quality water all the way down. And why “take out” water freed up by agricultural research and adaptation—rather, reinvest it. Finally, we must abandon the notion that the Murray can carry the task of returning salt to the sea, to revise the view that the mouth must remain open so much of the time, building an integrated drainage scheme as part of the whole.

A swagman camped by a billabong; a wanderer, one traversing the countryside and looking at many things, with time to think. As he slept in his camp, did he dream? Perhaps we need more swagmen having dreams to assist future making—like our grey nomads. Perhaps our old men should have dreams, and our young men should have visions—as part of our nation-building process, remembering history like Clarendon and Whyalla and Kalgoorlie, and Playford and Chifley, and East and Tisdall and Hudson, making grand new visions become realities in a future with imaginative new technologies and abundant renewable energy and creating new camping places by new billabongs.

Our grandchildren, the beneficiaries, can pay as they benefit.